> > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > > > index 4374cc6176..d9d3b1277a 100644 > > > --- a/hw/vfio/common.c > > > +++ b/hw/vfio/common.c > > > @@ -430,6 +430,9 @@ static void > > vfio_listener_region_add(MemoryListener *listener, > > > VFIOHostDMAWindow *hostwin; > > > bool hostwin_found; > > > > > > + if (!section->mr->ram_device) > > > + return; > > > + > > > > Nope, this would prevent IOMMU mapping of assigned device MMIO > > regions > > which would prevent peer-to-peer DMA between assigned devices. > Thanks, > > Understood. > > Is there a strong reason why QEMU allocates memory for these address > spaces without MAP_SHARED? In our use case it would solve our problem if > we could make QEMU use MAP_SHARED. I understand that this isn't strictly > correct, so would it be acceptable to enable this behavior with a command- > line option or an #ifdef?
Ping!
